The correct method of pH correction is dependant on the level of TDS (Total Dissolved Solids) in your water. A low maintenance and inexpensive way to proceed is use of an automatic backwashing pH neutralizer. However, if your TDS is high, you may need to use a chemical feed neutralizer.
To explain this we will need to review some background chemistry. The way in which a calcite neutralizer works is that the media (calcite - calcium carbonate, or Corosex - magnesium oxide) slowly dissolves into your water over time. The rate at which the calcite and/or Corosex can dissolve into you water is determined by your TDS. Dissolved solids are normally composed of your hardness constituents, as well as any iron, manganese and sodium present. If you already have a high amount of material dissolved into your water, the neutralization process will not work effectively using calcite neutralizer technology, and you would need to use a soda ash chemical feed neutralizer.
Both systems are described below, however, we would recommend that you send our lab a sample for analysis of your TDS if you do not have this information already available. Instructions for sampling your water mailing your water on our our Free Water Analysis page.
Automatic Backwashing pH Neutralizer
An automatic backwashing neutralizer uses a sacrificial media (calcium carbonate - calcite) that dissolves into your water over time to neutralize your water pH. The material is inexpensive, and you will need to refill your neutralizer tank approximately 1 to 2 times per year. The media can be purchased from us, or locally from a plumbing/water treatment supply house. In general, a pH above 6.4 and a TDS at 200 ppm or below can use a 1.5 ft3 N1-M mild acid condition neutralizer with calcite media.
Lower pH applications or applications with a higher TDS can use a 1.5 ft3 N1-S strong acid condition neutralizer with a 5:1 blend of calcite (calcium carbonate) and Corosex (magnesium oxide) media. Magnesium oxide is a stronger neutralizing agent when compared to calcium carbonate. If you suspect that your TDS and/or pH may require a stronger mix of calcite:Corosex, please E-mail or telephone us for a recommendation.
Both of these units feature the 1” Autotrol Performa 236/440i control and are supplied with a by-pass valve and the initial charge of calcite of calcite/Corosex mix media. It is typical to backwash these units automatically two times per week. This process adds some hardness to your water (4 to 5 grains), and you may want to consider installing a water softener after a backwashing pH neutralizer to remove any added hardness.
Chemical injection pH neutralizer system
The best method of pH correction at very low levels and/or high total dissolved solids is with use of a chemical injection system. A chemical injection system meters the soda ash solution directly into your water supply to neutralize your water pH. This method is not dependant on the level of TDS, and also adds no hardness to your water. However, it is a more expensive and maintenance intensive system.
Soda ash (sodium carbonate) is an inexpensive material, that is commonly available - from us - or locally at most plumbing supplies and water treatment dealers. Soda ash is supplied to you in powder form, and you dissolve it into solution.
This system is composed of a chemical feed pump, static mixer, solution storage tank and retention tank. When your well pump comes on, the chemical feed pump adds soda ash solution into the static mixer (which aids in the uniform mixing process) and enters a retention tank where the pH neutralization process occurs.
A general description and picture of the system is available on our Chemical Injection Systems page. Our system includes a Stenner STS chemical feed pump and solution storage tank system (ties in to well pump electrical, and only runs when your well pump is on), a 1" In-line static mixer to provide a convenient point of injection and improved in-line mixing, a 40 gallon retention tank, and a 50# bag of soda ash.
If you do not see the answer to your questions about the pH neutralization process and ways to correct water pH here, please let us know!